Tires: tire size cross ref, rim widths, size tire

Question
hi my 1968 coupe de ville manual lists a tire size as 9.00 15.  the tires on it are L78 15 and need to be replaced.  What size tire is the best fit now.  I have been told by a tire dealer that a 235.70.15 would work. I would like a second opinion.  thanks, mike

Answer
Mike,

A P235/75R15 is actually a better fit.  Just be aware that as time has moved on, the way tires are sized has also moved on, and the rim widths used back then are quite narrow compared to what we use today.  If you are using a stock rim, it will likely be too narrow for the tires of today, so you'll have to anticipate that there may be some wear and handling issues.